MALAKONDAIAH, P(MAJOR)CHENGALVA RAYULU, VRama Devi, VRAMANI PUSHPA, R.NJYOTHI SREE, Ch2018-12-012018-12-012017-11http://krishikosh.egranth.ac.in/handle/1/5810085015THESESABSTRACT: The present investigation has been undertaken to study the “Molecular characterization of Fasciola species in sheep and goats of Andhra Pradesh, India”. Slaughter/ necropsy examination of 5192 sheep and 2070 goats livers revealed 124 (2.38%) and 29 (1.40%) positive for Fasciola spp. with an overall prevalence rate of 2.10%. Higher prevalence was recorded in female sheep (3.50%) and goats (1.70%) than males of sheep (2.10%) and goats (1.24%), respectively. Highest prevalence was revealed in youngs (2.61% and 1.62%) than in adults (1.86% and 1.25% in 1-3 yrs and 2.11% and 1.22% in more than 3 years age) in sheep and goats, respectively. Highest infection rate was recorded in summer (2.89% & 1.53%) followed by winter (2.35% & 1.51%) and rainy seasons (1.19% & 0.91%) in sheep and goats, respectively. Present investigation also revealed that the prevalence of Fasciola spp. was the highest in April (6.05%) in sheep and in March (4.13%) for goats. Morphometric analysis was displayed large leaf like appearance of flukes with length and width ranged between 27.1 - Name of the author 36.5mm and 4.8 - 6.3mm in sheep and 27.5 - 38.1mm and 4.5 - 7.4mm in goats, respectively. Allometric values of Ventral Sucker to Posterior end (VS-P) and ratio of body length and width of adult flukes were 24.35-29.8mm and 4.71-6.29mm in sheep whereas 24.6-34.8mm and 4.89-6.73 mm in goats, respectively. Allometric values of the flukes collected in the present study were within the standard range (VS-P=26.8- 50.09mm, BL/BW=3.4-6.78mm) of F. gigantica and confirmed that the flukes from different parts of Andhra Pradesh were morphologically F. gigantica. Amplification of 275 genomic DNA samples (175 sheep and 100 goats) with their respective primers yielded a 433bp (ITS 1) and 550bp (ITS 2) products, respectively and confirmed them as Fasciola spp. Upon digestion with Rsa1 and BspHI restriction enzymes, the PCR-RFLP revealed a fragment of 233bp and 200bp in ITS 1 and 377bp and 173bp products in ITS 2 from all isolates of sheep (50) and goats (50), respectively. Sequencing analysis of randomly selected ITS 2 PCR products (3 sheep, 2 goats and 1 buffalo) revealed 100% homozygous within the species and a very few variations with the other geographical isolates. Pair wise distance analysis revealed 0% divergence in between them and 1-25% with the other geographical isolates of F. gigantica whereas 6% divergence with the F. hepatica. The phylogenetic analysis of ITS 2 sequences (6) revealed a close relationship with F. gigantica isolates of Asia (India, Iran, China, Thailand, South Korea, Vietnam, Indonesia, Pakistan) and Africa (Egypt, Zambia, Kenya, Mauritania). While the F. hepatica from Iran, Egypt, Australia and France were also exhibited relationship with the AP isolates and observed as a separate sub branch. The phylogeny of Andhra Pradesh isolates revealed that they were clustered in a same sub branch with regardless of their host, geographical origin and maternally inherited from F. gigantica.ennullThesis